The present invention relates to improvements in apparatus for manipulating elongated flexible webs or strips which consist of paper, cardboard, metallic foil, foamed synthetic plastic material, synthetic plastic material which confines bubbles or cushions of air or another gas, or the like. More particularly, the invention relates to improvements in apparatus for feeding seriatim discrete webs of flexible material toward and into a predetermined path wherein the webs advance toward and/or past one or more processing stations. Still more particularly, the invention relates to improvements in apparatus wherein successive webs are to be fed to one or more processing stations with a minimum of delay between the completion of feeding of a running web and the start of feeding of a fresh web.
It is already known to provide a web feeding apparatus with automatic means which can place, alternatively, two discrete reels of convoluted web material to a position for withdrawal of the web therefrom. The leader of the fresh web must be threaded into the transporting system by hand. In many instances, the width of gaps between successive webs cannot exceed a certain value so that the threading of the leader of a fresh web must be carried out by a highly skilled person to thereby insure that the leader of the fresh web is located practically immediately behind the trailing end of the preceding web. However, even if the work is performed by a highly skilled attendant, the apparatus must be slowed down or brought to a full stop which affects the output and might interfere with the operation of associated apparatus. If the leader of a fresh web is to be spliced to the trailing end of the preceding web, the attendant must apply one or more adhesive-coated uniting bands which is bound to further prolong the interval of idleness or the interval of operation at a reduced speed. Furthermore, the splicing operation normally involves trimming off the remnant of the preceding web behind the splice. Another serious drawback of the just described conventional apparatus and techniques is that an attendant must observe the operation in order to make sure that a fresh web will be introduced into the apparatus as soon as the supply of preceding web is exhausted or is about to be exhausted. If the webs are to be fed at an elevated speed, and if a reel contains a relatively small quantity of convoluted web material, the supply of expiring web must be monitored practically without any interruptions.